External condensate pipe freezing
Discussion
Hi All ,
Firstly many thanks to the forum owners and bloggers alike, you have just made me one very happy warm individual. I would like to recommend to any one with a combi boiler to filter through the advice on these threads, as they have loads of good advice. Heres a long summary of what I learnt today
For any one who is looking to get the quick fix for why their boiler isn't working try this:
I have a greenstar 30 cdi boiler, located in the roof,
Issue error light and on/off light flashing, and I think an EA error code.
Shockingly cold outside (sub zero).
I tried the usual reset of the system , and at first the system kicked back in , radiators got a little warm!! Then the heating had switched off again. Further resets resulted in no ignition of the system flame light (pilot light). On the greenstar this was about 40 seconds of almost positive sounding attempts to start but ending with the system stopping it's self.
From reading around on the net I decide that the Central Heating not working and the cold weather are most likely related, if a pipe being frozen is the problem and it's above 0 in the house , then it's more than likely the condensate pipe. I had no idea what this meant at first , but it appears that these CH units produce waste water , this generally runs out of the house, where it is below 0. If you have access to it I.E your boiler is downstairs or you have a ladder then go have a look and see if its frozen up, if so here in lies the problem ! I would recommend some boiling water , others have suggested hair driers .. defrost the pipe and hopefully you will have a little torrent of water shoot out when the ice goes , watch out~!
If like me you have no accesss to this pipe, how are you meant to defrost it ? The tip of the pipe has sealed up and causes a backlog of water into the CH , the unit senses the pressure and switches it's self off.
Solution, tried to defrost the pipe with a hair dryer from the inside. Could try a hot water bottle ... But realistically this is just going to be a repeat problem. Quite a lengthy affair and if your lofts like mine, quite a cramped one.
My immediate solution, open up the boiler and disconnect the condensate pipe, not a tricky job and no tools required on the greenstar aside the two screws to take the case off, it's a bit like a hoover arm stuck into a pipe on mine. Obviously if you can get a proff. to do this then just be safe and call out the fitter. Easy way to tell the condensate pipe is that it won't be copper , it should really be 22.5 mm waste pipe size, mines white but guess they probably use black as well. This should make it quite simple to identify (as water and gas should use copper).
I have read on this forum's thread that the responibility lies with the installer to make sure that this pipe dosn't get frozen, so feel free to give them some stick if they put up a fight on call out, there will also be some notes in the manual they left you about correct drainage instructions like angles!
If your unsure which is gas .. and your likely to be a bit heavy handed I would stay well clear of opening the boiler up, but if you have the manual it's really a 2 min job. Be careful to have a bucket at hand as the back pressure and built up water will more than likely go everywhere. A washing up bowl will do at first (if were talking you every day house boiler). Then redirect the hose to a storage container. This will get your heating up and running but your going to have to empty and dispose correctly of the water.
If your stuck without a longer term solution, and have to endure bouts of cold weather I would recommend something that can hold about 10 Litres and be replaced every 5 or so hours when on full use. Just a rough guide but seems to be right for me. I filled the washing up bowl a lot faster than I would of thought from the term condensate pipe !!!!!!
Long term solutions :
If the condensate pipe is accesible and your not worried about appearances, lag it, see previous posts for lag sizes but at the end of the day your trying to make it warmer, what ever works for you should be fine, another solution could be too widen the pipe, 32mm has been suggested as a thick enough width. Internal diversion if possible would work as well. There were some posts on here suggesting that you have to be careful about the solutes in the water and where you drain them to , so I would deffinitely consult the manual and nothing silly like run them back into your water supply !
Hopes this helps some one, I didnt think boilers went past the phase of pilot lights blowing out how silly I was, if you have stumbled onto this looking for how to relight a pilot light , your boilers new , I would give this a shot instead (new boilers very seldomly have the pilot light fail to light, if they do repair is essential and more than likely electrical, the pilot light not ignighting is more likely an over ride caused by somthing like the condensate pipe being blocked. remember to be safe!
Lastly can any one tell me why this is an actual problem in the first place ?? There are countries much colder than the UK and they dont have these problems >? Do they just divert it internally? Lastly to any designer!! a self unfreezing condensate pipe might be a good idea?? My view is that the ice works as a bung and the rest of the pipe is filled with liquid water! why not have a heating element that directly heats the condensate pipe if it senses that it's blocked?? Or maybe a button to do so ?
Firstly many thanks to the forum owners and bloggers alike, you have just made me one very happy warm individual. I would like to recommend to any one with a combi boiler to filter through the advice on these threads, as they have loads of good advice. Heres a long summary of what I learnt today
For any one who is looking to get the quick fix for why their boiler isn't working try this:
I have a greenstar 30 cdi boiler, located in the roof,
Issue error light and on/off light flashing, and I think an EA error code.
Shockingly cold outside (sub zero).
I tried the usual reset of the system , and at first the system kicked back in , radiators got a little warm!! Then the heating had switched off again. Further resets resulted in no ignition of the system flame light (pilot light). On the greenstar this was about 40 seconds of almost positive sounding attempts to start but ending with the system stopping it's self.
From reading around on the net I decide that the Central Heating not working and the cold weather are most likely related, if a pipe being frozen is the problem and it's above 0 in the house , then it's more than likely the condensate pipe. I had no idea what this meant at first , but it appears that these CH units produce waste water , this generally runs out of the house, where it is below 0. If you have access to it I.E your boiler is downstairs or you have a ladder then go have a look and see if its frozen up, if so here in lies the problem ! I would recommend some boiling water , others have suggested hair driers .. defrost the pipe and hopefully you will have a little torrent of water shoot out when the ice goes , watch out~!
If like me you have no accesss to this pipe, how are you meant to defrost it ? The tip of the pipe has sealed up and causes a backlog of water into the CH , the unit senses the pressure and switches it's self off.
Solution, tried to defrost the pipe with a hair dryer from the inside. Could try a hot water bottle ... But realistically this is just going to be a repeat problem. Quite a lengthy affair and if your lofts like mine, quite a cramped one.
My immediate solution, open up the boiler and disconnect the condensate pipe, not a tricky job and no tools required on the greenstar aside the two screws to take the case off, it's a bit like a hoover arm stuck into a pipe on mine. Obviously if you can get a proff. to do this then just be safe and call out the fitter. Easy way to tell the condensate pipe is that it won't be copper , it should really be 22.5 mm waste pipe size, mines white but guess they probably use black as well. This should make it quite simple to identify (as water and gas should use copper).
I have read on this forum's thread that the responibility lies with the installer to make sure that this pipe dosn't get frozen, so feel free to give them some stick if they put up a fight on call out, there will also be some notes in the manual they left you about correct drainage instructions like angles!
If your unsure which is gas .. and your likely to be a bit heavy handed I would stay well clear of opening the boiler up, but if you have the manual it's really a 2 min job. Be careful to have a bucket at hand as the back pressure and built up water will more than likely go everywhere. A washing up bowl will do at first (if were talking you every day house boiler). Then redirect the hose to a storage container. This will get your heating up and running but your going to have to empty and dispose correctly of the water.
If your stuck without a longer term solution, and have to endure bouts of cold weather I would recommend something that can hold about 10 Litres and be replaced every 5 or so hours when on full use. Just a rough guide but seems to be right for me. I filled the washing up bowl a lot faster than I would of thought from the term condensate pipe !!!!!!
Long term solutions :
If the condensate pipe is accesible and your not worried about appearances, lag it, see previous posts for lag sizes but at the end of the day your trying to make it warmer, what ever works for you should be fine, another solution could be too widen the pipe, 32mm has been suggested as a thick enough width. Internal diversion if possible would work as well. There were some posts on here suggesting that you have to be careful about the solutes in the water and where you drain them to , so I would deffinitely consult the manual and nothing silly like run them back into your water supply
! Hopes this helps some one, I didnt think boilers went past the phase of pilot lights blowing out how silly I was, if you have stumbled onto this looking for how to relight a pilot light , your boilers new , I would give this a shot instead (new boilers very seldomly have the pilot light fail to light, if they do repair is essential and more than likely electrical, the pilot light not ignighting is more likely an over ride caused by somthing like the condensate pipe being blocked. remember to be safe!
Lastly can any one tell me why this is an actual problem in the first place ?? There are countries much colder than the UK and they dont have these problems >? Do they just divert it internally? Lastly to any designer!! a self unfreezing condensate pipe might be a good idea?? My view is that the ice works as a bung and the rest of the pipe is filled with liquid water! why not have a heating element that directly heats the condensate pipe if it senses that it's blocked?? Or maybe a button to do so ?
willquick said:
Lastly can any one tell me why this is an actual problem in the first place ?? There are countries much colder than the UK and they dont have these problems >? Do they just divert it internally?
Funny you should bump this, as mine has just frozen up again. I knew I should have had the pipe re-routed in the summer! 
I think this is only an issue because of poor installation. The condensate pipe should run internally.
Hi, I have a slight variation on what seems to be a common problem. External Waste pipe frozen, partly because the waste pipe was running up to the guttering, and lack of lagging which I will sort out.
However when the pipe froze and backed up the boiler didn't cut out, resulting in condensate leaking out into the airing cupboard. The waste pipe from the boiler is 21.5mm but only drops about 6 inches from the boiler and hangs loose into a 32mm pipe connector. The bottom end of the connector also has a 21.5mm pipe inserted but does have a rubber seal to keep it tight.
So the result was when the waste froze and backed up it just flowed out of the top of the connector and the boiler kept running.
Firstly, are my suspicions correct that this is a shoddy piece of workmanship?
Secondly, and more importantly, is it ok to just get a 21.5mm connector to seal the waste run correctly?
Thanks for any advice you guys can offer
However when the pipe froze and backed up the boiler didn't cut out, resulting in condensate leaking out into the airing cupboard. The waste pipe from the boiler is 21.5mm but only drops about 6 inches from the boiler and hangs loose into a 32mm pipe connector. The bottom end of the connector also has a 21.5mm pipe inserted but does have a rubber seal to keep it tight.
So the result was when the waste froze and backed up it just flowed out of the top of the connector and the boiler kept running.
Firstly, are my suspicions correct that this is a shoddy piece of workmanship?
Secondly, and more importantly, is it ok to just get a 21.5mm connector to seal the waste run correctly?
Thanks for any advice you guys can offer
I have a nightmare with my condensate, it has been upgraded to 32mm and lagged. Yet it is frozen solid, it was not that cold today when it failed. Once it starts to freeze inside the pipe, the ice is constantly feed with fresh water. It will soon block any size pipe. The plumber is on about fitting a pump to routing it to a inside drain. I seem to think that a trace heater attached to the pipe and then lagged would be better.
Festive Ferg said:
Well, yes that's a bit poor. No real thought put into the installation..
But more worrying is the idea that it's been run to a gutter. Where is it going ultimately? Foul or storm drain? Or soakaway?
Thanks for the reply, But more worrying is the idea that it's been run to a gutter. Where is it going ultimately? Foul or storm drain? Or soakaway?
Have spent £1.05 on another reducer to provide a seal which seems to be doing the trick!
I think the downpipe from the guttering goes into a storm drain, although at the moment I've removed the pipes and it's just dripping into a large tub. Short term should this be disposed of into a foul drain, and long term would a soakaway be the best option to avoid freezing or lagging?
And finally, (due to my ignorance of plumbing/drainage issues), what does a soakaway drain consist of??
Ours went again yesterday, will last approx 2 weeks of freezing temps before it blocks and back pressure stops the boiler. Luckily we have flexi hose from boiler to pipe so acn disconnect and put in a bucket so we can restart boiler whilst defrosting external pipe.
Final flush with a salt water solution should clear it out a bit, till next time
Final flush with a salt water solution should clear it out a bit, till next time
what a carp piece of design... My glow worm is fitted to manufactures instructions and at the slightest frost freezes... I have insulated the outside pipe with 25mm insulation but it still freezes.
I am lucky in that the boiler is in the garage so I have an overflow pipe into a 5 ltr container but i pity people with boilers in the house with a pipe going outside...
Did manufactures not test this? the very time you need the heating it goes on the blink!
I am lucky in that the boiler is in the garage so I have an overflow pipe into a 5 ltr container but i pity people with boilers in the house with a pipe going outside...
Did manufactures not test this? the very time you need the heating it goes on the blink!
York Al said:
Short term should this be disposed of into a foul drain,
Yes. York Al said:
and long term would a soakaway be the best option to avoid freezing or lagging?
The soakway doesn't really help with the frezzing issue - it the pipe is outside and is too small and poorly routed (not enough fall) then it could still freeze.York Al said:
And finally, (due to my ignorance of plumbing/drainage issues), what does a soakaway drain consist of??
Google for condensate soakway - basically it's just a big piece of tube with some holes in it. You bury it vertically and put limestone chippings around it.buzzer said:
what a carp piece of design... My glow worm is fitted to manufactures instructions and at the slightest frost freezes... I have insulated the outside pipe with 25mm insulation but it still freezes.
I am lucky in that the boiler is in the garage so I have an overflow pipe into a 5 ltr container but i pity people with boilers in the house with a pipe going outside...
Did manufactures not test this? the very time you need the heating it goes on the blink!
+1I am lucky in that the boiler is in the garage so I have an overflow pipe into a 5 ltr container but i pity people with boilers in the house with a pipe going outside...
Did manufactures not test this? the very time you need the heating it goes on the blink!
Was hoping to go out partying tonight, but oh no the f
king condensate pipe freezes up (water pipe, running outside, freezing outside, pipe freezes... strange that 
) so I've got to stay in until its sorted. Tried with the kettle for over an hour but to no avail. 
Must... resist... getting... drill....
ETA Hairdryer works well tho
Edited by MarkRSi on Friday 24th December 09:55
Evening all. May aswell add myself to the list of affected
External condensate pipe, 40mm, frozen solid 3 days out of 4. Turns out the 40mm pipe was routed near horizontal at one point for a run of 60cm! Nice work. Boiler has been fitted for 2 years although new to us, we moved in only 2 months ago
Changed one of the joins from 90deg to 135deg and altered the run slightly. We shall see if it freezes again, good so far (4 days)
On the plus side I found out where the condensate trap is and gave it a much needed rinse
External condensate pipe, 40mm, frozen solid 3 days out of 4. Turns out the 40mm pipe was routed near horizontal at one point for a run of 60cm! Nice work. Boiler has been fitted for 2 years although new to us, we moved in only 2 months ago
Changed one of the joins from 90deg to 135deg and altered the run slightly. We shall see if it freezes again, good so far (4 days)
On the plus side I found out where the condensate trap is and gave it a much needed rinse
My pipe runs under floorboards from boiler in airing cupboard , through wall into attatched garage ,through garage front wall into outside drain ,it's lagged from garage to outside drain and has frozen at the end of the pipe for the last 2 weeks 
Now it's cut off inside garage and drips into bucket
No more defrosting pipe with kettle
Now it's cut off inside garage and drips into bucket
No more defrosting pipe with kettle
Hi,
I will add our system to this thread. In the past three days it has frozen overnight, even with the heating on 24/7. It is a Greenstar 30cdi with an external 32mm condensate pipe running from the first floor to ground level. The pipe is vertical down to where it enters a 4" foul (drain) pipe. This connection is an S shape. I think this is the trouble point. Two hot kettles normally fixes this, but a right pita at six in the morning for the pre work shower. Nearly got the hacksaw out to let it vent to atmosphere. Have to wait until the shops open before getting the lagging.
Andy..
I will add our system to this thread. In the past three days it has frozen overnight, even with the heating on 24/7. It is a Greenstar 30cdi with an external 32mm condensate pipe running from the first floor to ground level. The pipe is vertical down to where it enters a 4" foul (drain) pipe. This connection is an S shape. I think this is the trouble point. Two hot kettles normally fixes this, but a right pita at six in the morning for the pre work shower. Nearly got the hacksaw out to let it vent to atmosphere. Have to wait until the shops open before getting the lagging.
Andy..
Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff